The page above is a mess. I crossed out every original sentence but one and replaced them with new words. That should mean failure, right?
No, to me, that absolutely means success. This is, I think, the fourth play I ever wrote, "The Murder of Gonzago, and this is how I rewrote a scene that I especially liked. I gutted it and replaced it with all different stuff. In my opinion, better stuff. When you start writing plays, the rewriting is the hardest and least enjoyable part of the craft. "I already wrote this perfectly. Why do I have to change it?" The more plays you write, though, the more you enjoy rewriting.
If playwriting is truly a craft, these are the times when you can best show your craftsman ship. You're sanding down edges, you're shading things in, you're getting the curve of the nose of your sculpture exactly right. You got the story and characters generally right on the first pass (hopefully), but this is the time where you show you can make them shine. This is when you can make the world and the people in it just what you want. You'll never get the play in your head to match exactly the one that's on the paper, but the rewrites are where you go from 70% to 90% to 99%.
That page is a mess, true, but it's the best kind of mess.
(And yes, I'm well aware that I have terrible handwriting. But I'm a great typist!